| 摘要 |
A hydraulic brake pressure sensor, especially for motor vehicles, is described with a booster (4), to which servo pressure can be fed from an external energy supply system, at least one master cylinder piston being provided, which defines a working chamber, in which the brake pressure is built up and which can be connected by way of a valve device (76, 88) to a tank (94) at zero pressure. In order to achieve a transmission shift by simple structural means in the event of a servo power failure, it is proposed that the master cylinder piston (34) define a chamber (48), which is enlarged in the actuating direction when the master cylinder piston (34) is displaced and which can be connected by way of the valve device (76, 88) to the working chamber (36) and the compensating vessel (94). <IMAGE> |
